To provide a fuel injection control system and a fuel injection control method that improves drivability by reducing torque fluctuation and change in sound generated by an engine even when the presence/absence of pilot injection or pre-injection is switched.

An injector injects fuel into a combustion chamber by executing a main injection, a pre-injection or a pilot injection. The presence/absence of the pre-injection or pilot injection is switched depending on a load state of an engine body. If the pilot injection is switched from 'present' to 'absent', the injection timing Tm and injection quantity of the main injection and the injection timing Tpr and injection quantity of the pre-injection are varied. The fuel injection timing and injection quantity of the main injection and pre- injection are varied gradually within a given period from the switchover of the pilot injection from 'present' to 'absent' to thereby reduce torque fluctuation and change in generated sound.